(2G ) 



tlie unknown signification of the latter it is, to be sure, quite 

 uncertain whether there must exist a minimum limit beneath which 

 the possibility of life is totally excluded; but as this limit does 

 certainly exist for the facultatives, one is by analogy inclined to 

 accept its existence everywhere, consequently for the obligatous 

 anaërobics, too. That is, for them also, to recognise free oxygen as 

 a necessity for existence. 



This opinion has the more weight now that it has been proved 

 how easily may be shown that they not only use free oxygen but 

 if possible, seek it and that it may promote even such important 

 functions as growth and mobility. 



Without doubt, this points to something more than „use", albeit 

 the term „want" goes perhaps too far. As it is however a fact 

 that the obligatous anaërobics can produce thousands of new gene- 

 rations without a renewed contact with free oxygen, the hypothesis 

 demands the acceptance of a peculiar exciting action of the free 

 oxygen, stored up as a provision in the body of the bacteria. 



This action cannot be compared to that of kalium, or of magne- 

 sium, or of the other elements necessary for life in small quantities. 

 In the first place, because the latter must be present in quanti- 

 ties of another order, quantities gigantic compared to that of the 

 oxygen provision ; secondly and especially, because these elements 

 may be withdrawn from the most different chemical compounds. 

 The very necessity of the oxygen being free, causes the difficulty 

 of giving a definite representation of its function. Some light would 

 go up if it could be proved, that in the food a loosely bound 

 form of oxygen might occur, accessible to the anacrobics, and 

 Pasteur has indeed supposed that the oxygen, which is found in 

 beer wort, and cannot be separated from it by pom ping or boiling, 

 makes the anacrobiosis of beer yeast possible. 



Facts are however not in accordance with this hypothesis. Now, 

 as in the case of beer yeast and the other facultative anaërobics, we 

 are obliged to admit the existence of a store of free oxygen in 

 the cell itself, which, in a way hitherto unexplained, makes a 

 temporary anaërobiosis possible, analogy, supported by the observa- 

 tions here described, leads to the same conclusion for the obliga- 

 tous anaërobics. 



Physiology. — On the influence of solutions of salts on the volume 

 of animakeUs, being at the same time a contrihution to oiir 

 knowledge of their structure. By Dr. H. J. Hamburger. 

 ("Will be published in the Proceedings of the next meeting). 



